Blasting initiator loading machine



Dec. 1, 1953 c. R. JOHNSON ETAL BLASTING INITIATOR LOADING MACHINE Filed May 7. 1952 INVENTORS:

H. S-CHMID T n n a o v o v- CHARLES RUSSELL JOHNSON EDGAR C. R. JOHNSON EI'AL BLASTING INITIATOR LOADING MACHINE Dec. 1, 1953 4 Sheets-Sheet 2 Filed May 7, 1952 I INVENTORS: CHARLES RUSSELL JOHNSON and EDGAR H. scum/or 70:;- W

A rrogwvsys Dec. 1, 1953 c. R. JOHNSON ETAL 2,660,914

BLASTING INITIATOR LOADING MACHINE Filed May 7, 1952 4 Sheets-Sheet 3 INVENTORS CHARLES RUSSELL JOHNSON and EDGAR H. SCHMIDT A TTORNEYg.

c. R. JOHNSON ET AL BLASTING INITI ATOR LOADING MACHINE Dec. 1, 1953 4 Sheets-Sheet 4 Filed May '7, 1952 INVENTORS: CHARLES RUSSELL JOHNSON nd EDGAR H. SCHMIDT. -4- 64%, WA TTORNEYS .charge measurement. to provide a loading machine wherein cleaning is Patented Dec. 1, 1953 BLASTING INITIATOR LOADING MACHINE Charles Russell Johnson, Glenn Mills, Pa., and Edgar H. Schmidt, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application May 7 1952, Serial No. 286,532

, 5 Claims.

The present invention relates to a novel machine for loading accurately measured charges of explosive material into blasting initiator shells having a minimum amount of moving parts and possessing a high degree of safety.

Millions of blasting initiators are manufactured annually for various industrial users, and include such items as electric squibs and electric blasting caps, delay igniters, and blasting caps adapted to be fired by fuse. A basic component in each of the blasting initiators is a highly sensitive explosive composition, usually in the form of a powder. To insure uniformity and dependability, it is essential that the quantity of this basic component be identical in each initiator of a selected type. Due to the sensitivity of the composition, one of the most hazardous steps in the manufacture of explosive devices is the step of measuring and loading a predetermined amount of the ignition material into an initiator shell. While the quantity desired in each initiator is relatively small, accurate control of the measuring and of the insertion into the shell must be maintained with a minimum amount of human manipulation so as to reduce the hazard to personnel.

It has become the practice in the initiator manufacturing art to use apparatus adapted to be remotely controlled by an operator behind a barricade for this loading operation, and a number of such devices are well known. While the performance of the abovementioned machines is, in most cases, satisfactory for the conditions for which they are designed, they have not fully met the need of the industry for a loading machine having the high safety characteristic and accurate regulation of the charge and which is also adapted to load a large number of initiator shells automatically and with a minimum amount of operator manipulation. In addition, most of the prior art machines can not be adjusted to permit changes in the measurement of material and height of the initiator shell, and the cleaning of the machine continues to be a dangerous task.

It is an object of the present invention to provide a loading machine for blasting initiators which is adapted to accurately measure and load explosive charges automatically into blasting initiator shells, A further object is to provide such machine wherein a minimum amount of operator supervision is required. A still further object is to provide such machine wherein parts are readily interchangeable for adjustment in the An additional object is simplifiedand rendered non-hazardous. Addi- 2 tional objects will become apparent as the 'inven tionis furtherdescribed.

We have found that the foregoing objects may be attained when we provide a measuring plate containing a plurality of holes of equal volume extending the thickness of the plate, a means for temporarily closing the bottom ends of the holes, means for distributing explosive composition into and uniformly filling said holes, and a means for thereafter opening the bottom ends of the holes and directing the flow of explosive composition into initiator shells. In addition to the above, we desirably provide a means for locking all elements into the closed position, and inverting the plate for cleaning purposes. r 4

The present invention willbe more fully understood by reference to the accompanying drawings which illustrate a specific embodiment of the invention. It will be understood that the invention is not to be considered as limited to the embodiment shown in the drawings. I

In the drawings: 1

Figure 1 represents a front view and Figure 2 represents a top view of a complete machine embodying the features of the present invention;

Figure 3 represents a detail view of the hopper and measuring plate assembly;

Figure 4 represents a detail view of the measuring plate and sealing and nozzle plate construction;

Figures 5 and 6 represent enlarged views of the sealing element;

Figures 7, 8 and 9 represent views of the paddle and paddle drive mechanism; and

Figure 10 representsa side view of the mechanism illustrating the locking and dumping assembly.

Referring to the figures in greater detail, I is a tub shaped hopper mounted on a base plate 2. Mounted on the base plate 2 are support bearings 5, 6, and 1, the latter two being connected to each other by the strengthening rib 8. Shaft 9 passes through bearings 5 and 6, thereby supporting base plate 2, and is in turn supported by the terminal bearing I0 and housing H, the bearing I0 and the housing ll being mounted on the main framework l2. The framework l2 rests on the supporting surface of floor and consists of structural steel beams welded or riveted in the desired arrangement.

The base plate 2 is additionally supported by the pins [3 extending from the framework l2 and nesting in the guide plates M. A vibrator I5 is mounted on the base plate 2 adjacent to the hopper I.

Centrally positioned within the hopper and supported by the base plate 2 is the measuring plate I1 containing openings 39. Suspended below plate H is the nozzle plate 40 containing downwardly projecting nozzles 16 and upwardly projecting resilient sealing elements 38. The plate 4|! is suspended on four rack-pins H which extend within the housings l8 and 19 mounted on base plate 2 at the front and rear of the hopper l and are in engagement with teeth 42 cut into shafts 9 and 20, shaft 9 passing through housing l8, and shaft 20 passing through housing f9. Shafts 9 and 29 are interconnected :by means rof yoke 2|. A flexible sheathing flearoun'd each'gpin 4| prevents powder from gathering around the e --iace 'of the measuring plate H. The crosshead 121 contains the rack-Thar :45 guided -by "extension 45 within the dril'led guide passage 46. Cam 3 roller 4:1 is fastened :to rack-bar "44 and 'operates in cam track -48 of :cam 3|. Cam roller k9 is fastened directly to crosshead and zoperates in ca-m'track fill of 'cam 32. The cams 3| and '32 are slidably mounted =on shaft 30 -'containin'g feather key 28. Mounted on the framework l2 are the cam :rollers :53 and 59, in engagement with :cam tracks 48 and 50, respectively.

=Adj aoent to therhousing Iisthe dump 'mechanism housing 22 which surrounds shaft 9 rand contains a rack-bar 4 tin :engagement with gear 54, mounted on the housing iof rsupport bearing 6. :Rack-barfl is actuated by hydraulic omit 23. The housing -'contains 'eam track =51 which guides 'cam roller '55 mounted on yoke 121 Yoke 2| when'the hopper I is innorm'alzpo'sition, is in engagement with operating pin 515.

The hopper in this particular construction contams a powder shelf 3 completely "around "the periphery, and is made in two sections which are joined together :by rivets 33 in flanges 34.

The operation of the loading 'mamriine of the :present invention is as follows: A quantity of ignition composition is dumped, teither mechanically or by operator, into the powder hopper 4.. A blU'flk of empty iinitiator shells is fed *into space 25 of shelf 24, and locked into position so rth'atthe open ends of the sh'ells :a're fdinectly'under lthe'n'ozzl'es -16. :Ihis operationunaybe'per'formed either automatically or as 78111 individual operation.

shaft is now slowly rotated (the *drive mechanism not being shown) 'in the direction indicated in Figure 7. Due to the contour of track '48, the cam roller .is moved toward the right, and ram -3 also moves to the right, this :latter motion being produced 'by the action of cam *roller :58 in cam track 18. During th'e first :91) degrees :of rotation of shaft the cam 32 maintains its relative position on shaft 30, and the crossheadifi remains stationary. Thus rack 44 moves to ".the'right within crosshead 'rotat- Zing rpa'ddl'e shaft 29 "90 degreesnnd moving paddl'e -:blade .6! :clownward into the hoppernpushin'g powder ahead of it. Further rotation of :shaft Paddle blade 52 acontains :a tri- TIO 4 30 produces a movement to the right 01 cams 3| and 32, and of crosshead 21, the shaft 29 being carried to the right without further rotation. Paddle blade 5| thus distributes a uniform layer of powder over measuring plate |'l. When the crosshead 21 is in its extreme righthand position "(180 degrees rotation .ofshaft30), rfurther rotation of shaft 39 moves cam 3| towards the left and cam roller 41 is also moved to the left, while the crosshead and cam 32 remain at the right- .ha'ndgposition. This motion reverses the rotation of paddle shaft '29,"thus restoring it to the original lposition,.i.=e., blade 152 downward into the hopper.

.Duning tlfisn otation of the paddle shaft 29, the compressed air vibrator I5 is actuated. The vibrator l5 imparts sufficient vibration to the base-plate 2 to .cause the loose powder over measuring plate I! to fill completely the holes 36, the muzzle plate 40 being in the raised position.

The remaining degrees rotation of shaft 30 moves the crosshead '21 to the left without "further rotation 'of the paddle shaft 29, thus ldrawzing :paddle blade '52 cover the measuring \plate =|-'1. "The :strip 53 of resilient material afastened (to-the bottom of blade 52 .wipes the surface of measur- ,-plate 151 free of :powder without disturbing the powder in holes 38, and piles the excess :pow- -der=on the lefthand side of hopper nompl'etes one cycle of thepaddle assemlilypperation, and-after a short/pause, :the second cycle :is oom- 'menced. the period lthat the rpaiilileiis stationary, operating .pin :55 is moved by mechanism not "shown, towards "the paddle assembly side of the apparatus, thereby .moving the yoke '21,, and rotating shafts 9 and MI. rotation lowers the :pins H, dropping nozzle. plate 40 towards the initiator shells, :and releasing ithe sealing elements 38 rfirom contact with openings 36. -Vibrator 45 is again animated, and :powderrin the openings $16 :drops [through the openings :39 :in the fStEIIlS of the sealing members .38 rand :out of the FIIDZZIES 1:6 .into the initiator :shells. 'The 55 .is then trecipro'oated to its original position, returning the yoke all, and thereby raising the nozzle rplate 40 so that the sealing members 38 again close the ibottoms of the openings 36. The :initia'tor shell block is ."now #removed and replaced with :a block rcontaiin'ing empty shells, and the entire operating rcycle resumed.

:It will he understood, of course, "that the :sequence of operation rdesorihed above is synchromized by conventional means, and dzhat :an initial :supply of powder in the hopper 1 will 'movide enough bulk :material :for from 'twenty to *seventy cycles of zloadnrg rbefore a new supply is required. 'Thermecha'nism' rnay be actuated by'a'ny conven- :tional :motive means, such as .an electric motor, zmamrif rdesiredfbe so geared that a-sing'l'e .zsource of :power will provide all :of the :rnot'ive power. The type of motor :and "the mechanism used $120 produce the sdesired :movenrentsof the varionselementsii. e, the cam shaft 30, thevibrator l5, and the mperatmg iljln 55, are mot :a part ofathe qaresentiinventiongahii are, according lygnot illustrated or fdescribed :herein.

The present mechanism is adapted to be operated either as an individual unit, or as part of a general initiator assembly line. If used in oomibinati'on with other operating units, "the "speed 0f roperation will, of oourse, be regulated to m'eetthe requirements of the dine. :Forexample, using the described apparatus, :"5000 initiators fhave been :l'oaded 1 in onelhonrnwithoutexperiencing any difdioulty. Ellhenrawingzillustmtesainozzle pl'ateand measuring ED127138 montain'ing "openings, thereby limiting the loading capacity to 100 initiators per cycle. A plate of this capacity need be only seven inches in length and width. Obviously, it is entirely feasible to use larger plates having more openings if desired.

The i easuring plate may be removed very simply and replaced with one having smaller or larger openings. This permits accurate regulation of the quantity of ignition powder per unit charge, and the apparatus can thus be rapidly adjusted to meet changing specification of loading. There are a minimum amount of moving parts contacted by the sensitive eXplOsiVe composition, thus reducing the hazard of explosion. Only a small quantity of the explosive is present in the apparatus at any one time, so that the force of any accidental detonation would be relatively slight. The explosive is not under confinement, and any detonation would cause only slight damage, if any.

The described machine is very easy to clean. By mechanism not shown, the crosshead 2! is tilted up so as to lift the paddles out of hopper I. By actuation of hydraulic unit 23, the rack-bar 4 is moved downwardly, thus rotating base plate 2. Before pin 55 becomes disengaged from yoke 2|, cam-roller 55 enters the cam-track 51 in housing 1 I, and the yoke 2| is thus prevented from lateral movement during the dumping operation. By this action, the sealing elements 38 are maintained in contact with the openings 35, and powder in the hopper I cannot pass through the openings. A tub or similar receptacle can be provided to catch the powder being dumped as the tub I is inverted, and substantially all of the powder will thus be removed. It is then possible to complete the cleaning and changing of the plates, etc., without danger. To restore the machine to its operating position, the rack-bar 4 is raised by the hydraulic unit 23 until the base-plate 2 rests on the pins l3, and the paddle assembly is returned to its initial position.

While the present invention has been described in considerable detail with reference to the particular embodiment shown, it will be understood that many variations may be made. The arrangement of the paddle drive, for example, may be replaced with any conventional arrangement for accomplishing the desired movement of the paddle blades. We intend, therefore, to be limited only by the following claims.

We claim:

1. In an apparatus for loading explosive charges into initiator shells, the combination comprising a hopper, a flat base plate in the lower portion of said hopper, said base plate containing a plurality of apertures perpendicular to the surface thereof and of equal size, a nozzle-plate beneath said 'base plate, said nozzle-plate containing downwardly projecting nozzles and upwardly projecting mushroom-shaped sealing elements in axial alignment with said apertures in the base plate, said sealing members having a head of larger diameter than the diameter of said aperture, and openings in the base communicating with said nozzles, means for depositing explosive composition into each of said apertures, and means for vertically reciprocating said nozzleplate.

2. In an apparatus as claimed in claim 1, the combination wherein the sealing elements are of a rubber-like resilient material.

3. In an apparatus as claimed in claim 1, the combination wherein the depositing means comprises a paddle mechanism.

4. In an apparatus as claimed in claim 1, the combination wherein the depositing means comprises a two-bladed paddle mounted on a shaft capable of being rotated and of being moved horizontally, one of said blades reaching to a point above the surface of said base plate and the other blade reaching to the surface of said base plate.

5. ,An apparatus as claimed in claim 1, wherein said hopper is pivotably mounted and mechanical means are provided for inverting said hopper.

CHARLES RUSSELL JOHNSON. EDGAR I-I. SCHMIDT.

No references cited. 

